As Hurricane Sandy loomed closer to the Northeast coast on Saturday afternoon, Governor Deval Patrick declared a state of emergency in preparation for power outages, coastal flooding, and beach erosion that could rock the New England region.

The Bay State will begin feeling the hurricane’s effects Sunday evening, said National Weather Service meteorologist Kim Buttrick, but not its full force until Monday.

Winds will start blowing 35 to 45 miles per hour on Monday in Massachusetts, with gusts up to 55
miles per hour in the morning that will accelerate in the afternoon, reaching a peak of 65 miles per hour. Higher-than-average winds and precipitation will continue until Tuesday morning, Buttrick said.

On Saturday evening, the storm remained a Category 1 storm hovering 340 miles off the Outer Banks in North Carolina. As it passed over Haiti, Jamaica, Cuba, and the Bahamas, it killed at least 58 people, in addition to damaging or destroying thousands of homes. Category 1 is the least severe ranking of a hurricane with winds averaging 74 to 95 miles per hour.

Buttrick said the storm’s center is expected to arrive on the southern New Jersey coast during the day Sunday, and beachfront residents in nearby Delaware have been ordered to evacuate their homes. But the storm’s large size — 500 to 700 miles in diameter, Buttrick said — means Massachusetts residents will still bear some of its brunt.

“Hurricane or not, whatever it is, when it hits us, it’s going to be a storm of great impact and magnitude,” Buttrick said.

Boston-area residents can expect 1 to 2 inches of precipitation, though communities in the Berkshires could see up to 5 inches. The storm remains unpredictable because it is set to collide with a dipping jet stream as well as a strong high pressure system moving south from eastern Canada, Buttrick said, but that is not certain. The potential combination of forces has prompted some to dub the hurricane “Frankenstorm.” That is not a term the National Weather Service endorses, Buttrick said, but the mix of weather systems means that this hurricane is one to watch out for.

“All these ingredients coming together — it’s history-making,” she said.

Because of the full moon on Monday, tides will be high, causing greater risk of coastal flooding and beach erosion, which Massachusetts’ shoreline communities are preparing for.

“This storm Sandy is churning up the sea,” Buttrick said. “It’s going to pile up water along our coastlines.”

At an afternoon press conference in Framingham, Patrick said 200 members of the National Guard have been mobilized in Massachusetts. That number will ramp up to 1,000 or more by Monday.

Patrick said he planned to submit a preemptive request to President Obama for a disaster declaration, just as he did before last year’s Hurricane Irene. The disaster declaration will help the state receive direct federal assistance in the aftermath of the storm.

“While we continue to hope for the best, we’re preparing for the worst,” Patrick said.

State officials have given stern mandates to electricity companies such as NStar to improve response times and communication with local officials and residents, or face fines.

“They’re going to be judged on their response and how they perform on the ground,” said Energy and Environmental Affairs Secretary Rick Sullivan.

NStar spokesman Michael Durand said the company has beefed up its ranks of community liaisons and support staff to 92 people. These individuals will be assigned to specific communities where they will serve as a primary point-persons for emergency responders and local leaders, who will be able to report downed wires and outages in real time through a Web-based reporting tool.

“These liaisons will be available to communities 24/7, working throughout the day and night,” Durand said, adding that the liaisons will be stationed in facilities close to the communities they cover. “These communities will have a dedicated person to speak with to resolve issues.”

Additionally, for the first time, customers will also be able to report outages on NStar’s website using computers or their smart phones, Durand said. And in the hours before the hurricane, the company sent robo-calls to customers reminding them to stay safe during the storm and providing information on reporting power outages.

Hurricane Sandy is expected to cause heavy beach erosion along the Massachusetts coastline — a phenomenon that is a special risk on Plum Island on Newburyport.

On Saturday police began calling Plum Island residents to warn them an evacuation order could be issued as early as Sunday evening.

On Friday and Saturday, bulldozers were working during low tide to move about 2,000 cubic yards of sand to protect homes precariously close to the water.

On Saturday morning, resident Bob Connors stood amid the blustery wind and fog to get a good look at the progress. Sand had been pushed up from the lower part of the beach, reinforcing dunes with a sand wall about 4 to 6 feet tall to keep anticipated storm surges from eating away at the shoreline.

“It’s the area most at risk,” said Connors, lead organizer of the Coastal Property Owners Association, the group funding the effort. “These homes could be all at risk if this [storm] becomes an event.”

David Williamson, a resident of Plum Island for more than 20 years, said the beach scraping is going to cost him between $900 and $1,000. “It’s a very small price to pay to save your home,” said Williamson.

The Federal Emergency Management Agency has deployed assistance teams up and down the East Coast, and the agency is amassing supplies such as food, water, and blankets at bases along the northeast coast that may be needed during the recovery.

In Boston, public safety agencies have ramped up staff to respond to problems during the duration of the storm, according to a statement from Mayor Thomas M. Menino’s office.

“The city of Boston has been gearing up for this for several days,” said Boston Police superintendent William Evans. “Based on past storms, our main concerns are power wires coming down and trees blocking roads.”

Boston public school officials are also being included in preparations, Evans said, adding that there is a possibility that school may be canceled, especially if buses are unable to complete their routes because of downed trees.

Evans said that Boston residents should secure any loose items on their property, like Halloween decorations or patio furniture, and remain indoors during the storm. “If you don’t have to go out, please don’t,” he said, citing the need for emergency vehicles to move quickly.

According to the National Weather Service, Sunday will have highs in the the mid- and upper 50s, and winds of 10 to 20 miles per hour, Buttrick said. Rain is expected to start in the evening.

Boston Police Harbormaster Joe Cheevers urged thrill-seekers not to go out on piers, seawalls, or other locations where waves could sweep people into the water.

“Everybody wants to see the surf, but your best bet is to stay away from the sea,” he said. “It’s great to see Mother Nature in action, but you’re really taking your life into your own hands.”

In bustling Salem, ghost tour operator Tim Maguire Jr. hoped the impending storm would not affect business. Sandy’s approach was reminiscent of last year’s Halloween weekend, when a freak nor’easter walloped the region.

“I had 450 no-shows and it cost me $17,000,” Maguire said.

For Maguire, the start of the season, around Columbus Day, is his busiest, but he said he anticipates a loss of business starting Monday due to Sandy.

“I’ll probably have half no-shows,” he said.

Globe correspondents Katheleen Conti and Dan Adams contributed to this report. Martine Powers can be reached at mpowers@globe.com. Follow her on Twitter @martinepowers.